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1723 lines (1431 loc) · 51.6 KB
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// layout.h -- lay out output file sections for gold -*- C++ -*-
// Copyright (C) 2006-2019 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.
#ifndef GOLD_LAYOUT_H
#define GOLD_LAYOUT_H
#include <cstring>
#include <list>
#include <map>
#include <string>
#include <utility>
#include <vector>
#include "script.h"
#include "workqueue.h"
#include "object.h"
#include "dynobj.h"
#include "stringpool.h"
namespace gold
{
class General_options;
class Incremental_inputs;
class Incremental_binary;
class Input_objects;
class Mapfile;
class Symbol_table;
class Output_section_data;
class Output_section;
class Output_section_headers;
class Output_segment_headers;
class Output_file_header;
class Output_segment;
class Output_data;
class Output_data_reloc_generic;
class Output_data_dynamic;
class Output_symtab_xindex;
class Output_reduced_debug_abbrev_section;
class Output_reduced_debug_info_section;
class Eh_frame;
class Gdb_index;
class Target;
struct Timespec;
// Return TRUE if SECNAME is the name of a compressed debug section.
extern bool
is_compressed_debug_section(const char* secname);
// Return the name of the corresponding uncompressed debug section.
extern std::string
corresponding_uncompressed_section_name(std::string secname);
// Maintain a list of free space within a section, segment, or file.
// Used for incremental update links.
class Free_list
{
public:
struct Free_list_node
{
Free_list_node(off_t start, off_t end)
: start_(start), end_(end)
{ }
off_t start_;
off_t end_;
};
typedef std::list<Free_list_node>::const_iterator Const_iterator;
Free_list()
: list_(), last_remove_(list_.begin()), extend_(false), length_(0),
min_hole_(0)
{ }
// Initialize the free list for a section of length LEN.
// If EXTEND is true, free space may be allocated past the end.
void
init(off_t len, bool extend);
// Set the minimum hole size that is allowed when allocating
// from the free list.
void
set_min_hole_size(off_t min_hole)
{ this->min_hole_ = min_hole; }
// Remove a chunk from the free list.
void
remove(off_t start, off_t end);
// Allocate a chunk of space from the free list of length LEN,
// with alignment ALIGN, and minimum offset MINOFF.
off_t
allocate(off_t len, uint64_t align, off_t minoff);
// Return an iterator for the beginning of the free list.
Const_iterator
begin() const
{ return this->list_.begin(); }
// Return an iterator for the end of the free list.
Const_iterator
end() const
{ return this->list_.end(); }
// Dump the free list (for debugging).
void
dump();
// Print usage statistics.
static void
print_stats();
private:
typedef std::list<Free_list_node>::iterator Iterator;
// The free list.
std::list<Free_list_node> list_;
// The last node visited during a remove operation.
Iterator last_remove_;
// Whether we can extend past the original length.
bool extend_;
// The total length of the section, segment, or file.
off_t length_;
// The minimum hole size allowed. When allocating from the free list,
// we must not leave a hole smaller than this.
off_t min_hole_;
// Statistics:
// The total number of free lists used.
static unsigned int num_lists;
// The total number of free list nodes used.
static unsigned int num_nodes;
// The total number of calls to Free_list::remove.
static unsigned int num_removes;
// The total number of nodes visited during calls to Free_list::remove.
static unsigned int num_remove_visits;
// The total number of calls to Free_list::allocate.
static unsigned int num_allocates;
// The total number of nodes visited during calls to Free_list::allocate.
static unsigned int num_allocate_visits;
};
// This task function handles mapping the input sections to output
// sections and laying them out in memory.
class Layout_task_runner : public Task_function_runner
{
public:
// OPTIONS is the command line options, INPUT_OBJECTS is the list of
// input objects, SYMTAB is the symbol table, LAYOUT is the layout
// object.
Layout_task_runner(const General_options& options,
const Input_objects* input_objects,
Symbol_table* symtab,
Target* target,
Layout* layout,
Mapfile* mapfile)
: options_(options), input_objects_(input_objects), symtab_(symtab),
target_(target), layout_(layout), mapfile_(mapfile)
{ }
// Run the operation.
void
run(Workqueue*, const Task*);
private:
Layout_task_runner(const Layout_task_runner&);
Layout_task_runner& operator=(const Layout_task_runner&);
const General_options& options_;
const Input_objects* input_objects_;
Symbol_table* symtab_;
Target* target_;
Layout* layout_;
Mapfile* mapfile_;
};
// This class holds information about the comdat group or
// .gnu.linkonce section that will be kept for a given signature.
class Kept_section
{
private:
// For a comdat group, we build a mapping from the name of each
// section in the group to the section index and the size in object.
// When we discard a group in some other object file, we use this
// map to figure out which kept section the discarded section is
// associated with. We then use that mapping when processing relocs
// against discarded sections.
struct Comdat_section_info
{
// The section index.
unsigned int shndx;
// The section size.
uint64_t size;
Comdat_section_info(unsigned int a_shndx, uint64_t a_size)
: shndx(a_shndx), size(a_size)
{ }
};
// Most comdat groups have only one or two sections, so we use a
// std::map rather than an Unordered_map to optimize for that case
// without paying too heavily for groups with more sections.
typedef std::map<std::string, Comdat_section_info> Comdat_group;
public:
Kept_section()
: object_(NULL), shndx_(0), is_comdat_(false), is_group_name_(false)
{ this->u_.linkonce_size = 0; }
// We need to support copies for the signature map in the Layout
// object, but we should never copy an object after it has been
// marked as a comdat section.
Kept_section(const Kept_section& k)
: object_(k.object_), shndx_(k.shndx_), is_comdat_(false),
is_group_name_(k.is_group_name_)
{
gold_assert(!k.is_comdat_);
this->u_.linkonce_size = 0;
}
~Kept_section()
{
if (this->is_comdat_)
delete this->u_.group_sections;
}
// The object where this section lives.
Relobj*
object() const
{ return this->object_; }
// Set the object.
void
set_object(Relobj* object)
{
gold_assert(this->object_ == NULL);
this->object_ = object;
}
// The section index.
unsigned int
shndx() const
{ return this->shndx_; }
// Set the section index.
void
set_shndx(unsigned int shndx)
{
gold_assert(this->shndx_ == 0);
this->shndx_ = shndx;
}
// Whether this is a comdat group.
bool
is_comdat() const
{ return this->is_comdat_; }
// Set that this is a comdat group.
void
set_is_comdat()
{
gold_assert(!this->is_comdat_);
this->is_comdat_ = true;
this->u_.group_sections = new Comdat_group();
}
// Whether this is associated with the name of a group or section
// rather than the symbol name derived from a linkonce section.
bool
is_group_name() const
{ return this->is_group_name_; }
// Note that this represents a comdat group rather than a single
// linkonce section.
void
set_is_group_name()
{ this->is_group_name_ = true; }
// Add a section to the group list.
void
add_comdat_section(const std::string& name, unsigned int shndx,
uint64_t size)
{
gold_assert(this->is_comdat_);
Comdat_section_info sinfo(shndx, size);
this->u_.group_sections->insert(std::make_pair(name, sinfo));
}
// Look for a section name in the group list, and return whether it
// was found. If found, returns the section index and size.
bool
find_comdat_section(const std::string& name, unsigned int* pshndx,
uint64_t* psize) const
{
gold_assert(this->is_comdat_);
Comdat_group::const_iterator p = this->u_.group_sections->find(name);
if (p == this->u_.group_sections->end())
return false;
*pshndx = p->second.shndx;
*psize = p->second.size;
return true;
}
// If there is only one section in the group list, return true, and
// return the section index and size.
bool
find_single_comdat_section(unsigned int* pshndx, uint64_t* psize) const
{
gold_assert(this->is_comdat_);
if (this->u_.group_sections->size() != 1)
return false;
Comdat_group::const_iterator p = this->u_.group_sections->begin();
*pshndx = p->second.shndx;
*psize = p->second.size;
return true;
}
// Return the size of a linkonce section.
uint64_t
linkonce_size() const
{
gold_assert(!this->is_comdat_);
return this->u_.linkonce_size;
}
// Set the size of a linkonce section.
void
set_linkonce_size(uint64_t size)
{
gold_assert(!this->is_comdat_);
this->u_.linkonce_size = size;
}
private:
// No assignment.
Kept_section& operator=(const Kept_section&);
// The object containing the comdat group or .gnu.linkonce section.
Relobj* object_;
// Index of the group section for comdats and the section itself for
// .gnu.linkonce.
unsigned int shndx_;
// True if this is for a comdat group rather than a .gnu.linkonce
// section.
bool is_comdat_;
// The Kept_sections are values of a mapping, that maps names to
// them. This field is true if this struct is associated with the
// name of a comdat or .gnu.linkonce, false if it is associated with
// the name of a symbol obtained from the .gnu.linkonce.* name
// through some heuristics.
bool is_group_name_;
union
{
// If the is_comdat_ field is true, this holds a map from names of
// the sections in the group to section indexes in object_ and to
// section sizes.
Comdat_group* group_sections;
// If the is_comdat_ field is false, this holds the size of the
// single section.
uint64_t linkonce_size;
} u_;
};
// The ordering for output sections. This controls how output
// sections are ordered within a PT_LOAD output segment.
enum Output_section_order
{
// Unspecified. Used for non-load segments. Also used for the file
// and segment headers.
ORDER_INVALID,
// The PT_INTERP section should come first, so that the dynamic
// linker can pick it up quickly.
ORDER_INTERP,
// Loadable read-only note sections come next so that the PT_NOTE
// segment is on the first page of the executable.
ORDER_RO_NOTE,
// Put read-only sections used by the dynamic linker early in the
// executable to minimize paging.
ORDER_DYNAMIC_LINKER,
// Put reloc sections used by the dynamic linker after other
// sections used by the dynamic linker; otherwise, objcopy and strip
// get confused.
ORDER_DYNAMIC_RELOCS,
// Put the PLT reloc section after the other dynamic relocs;
// otherwise, prelink gets confused.
ORDER_DYNAMIC_PLT_RELOCS,
// The .init section.
ORDER_INIT,
// The PLT.
ORDER_PLT,
// The hot text sections, prefixed by .text.hot.
ORDER_TEXT_HOT,
// The regular text sections.
ORDER_TEXT,
// The startup text sections, prefixed by .text.startup.
ORDER_TEXT_STARTUP,
// The startup text sections, prefixed by .text.startup.
ORDER_TEXT_EXIT,
// The unlikely text sections, prefixed by .text.unlikely.
ORDER_TEXT_UNLIKELY,
// The .fini section.
ORDER_FINI,
// The read-only sections.
ORDER_READONLY,
// The exception frame sections.
ORDER_EHFRAME,
// The TLS sections come first in the data section.
ORDER_TLS_DATA,
ORDER_TLS_BSS,
// Local RELRO (read-only after relocation) sections come before
// non-local RELRO sections. This data will be fully resolved by
// the prelinker.
ORDER_RELRO_LOCAL,
// Non-local RELRO sections are grouped together after local RELRO
// sections. All RELRO sections must be adjacent so that they can
// all be put into a PT_GNU_RELRO segment.
ORDER_RELRO,
// We permit marking exactly one output section as the last RELRO
// section. We do this so that the read-only GOT can be adjacent to
// the writable GOT.
ORDER_RELRO_LAST,
// Similarly, we permit marking exactly one output section as the
// first non-RELRO section.
ORDER_NON_RELRO_FIRST,
// The regular data sections come after the RELRO sections.
ORDER_DATA,
// Large data sections normally go in large data segments.
ORDER_LARGE_DATA,
// Group writable notes so that we can have a single PT_NOTE
// segment.
ORDER_RW_NOTE,
// The small data sections must be at the end of the data sections,
// so that they can be adjacent to the small BSS sections.
ORDER_SMALL_DATA,
// The BSS sections start here.
// The small BSS sections must be at the start of the BSS sections,
// so that they can be adjacent to the small data sections.
ORDER_SMALL_BSS,
// The regular BSS sections.
ORDER_BSS,
// The large BSS sections come after the other BSS sections.
ORDER_LARGE_BSS,
// Maximum value.
ORDER_MAX
};
// This class handles the details of laying out input sections.
class Layout
{
public:
Layout(int number_of_input_files, Script_options*);
~Layout()
{
delete this->relaxation_debug_check_;
delete this->segment_states_;
}
// For incremental links, record the base file to be modified.
void
set_incremental_base(Incremental_binary* base);
Incremental_binary*
incremental_base()
{ return this->incremental_base_; }
// For incremental links, record the initial fixed layout of a section
// from the base file, and return a pointer to the Output_section.
template<int size, bool big_endian>
Output_section*
init_fixed_output_section(const char*, elfcpp::Shdr<size, big_endian>&);
// Given an input section SHNDX, named NAME, with data in SHDR, from
// the object file OBJECT, return the output section where this
// input section should go. RELOC_SHNDX is the index of a
// relocation section which applies to this section, or 0 if none,
// or -1U if more than one. RELOC_TYPE is the type of the
// relocation section if there is one. Set *OFFSET to the offset
// within the output section.
template<int size, bool big_endian>
Output_section*
layout(Sized_relobj_file<size, big_endian> *object, unsigned int shndx,
const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
unsigned int sh_type, unsigned int reloc_shndx,
unsigned int reloc_type, off_t* offset);
std::map<Section_id, unsigned int>*
get_section_order_map()
{ return &this->section_order_map_; }
// Struct to store segment info when mapping some input sections to
// unique segments using linker plugins. Mapping an input section to
// a unique segment is done by first placing such input sections in
// unique output sections and then mapping the output section to a
// unique segment. NAME is the name of the output section. FLAGS
// and ALIGN are the extra flags and alignment of the segment.
struct Unique_segment_info
{
// Identifier for the segment. ELF segments don't have names. This
// is used as the name of the output section mapped to the segment.
const char* name;
// Additional segment flags.
uint64_t flags;
// Segment alignment.
uint64_t align;
};
// Mapping from input section to segment.
typedef std::map<Const_section_id, Unique_segment_info*>
Section_segment_map;
// Maps section SECN to SEGMENT s.
void
insert_section_segment_map(Const_section_id secn, Unique_segment_info *s);
// Some input sections require special ordering, for compatibility
// with GNU ld. Given the name of an input section, return -1 if it
// does not require special ordering. Otherwise, return the index
// by which it should be ordered compared to other input sections
// that require special ordering.
static int
special_ordering_of_input_section(const char* name);
bool
is_section_ordering_specified()
{ return this->section_ordering_specified_; }
void
set_section_ordering_specified()
{ this->section_ordering_specified_ = true; }
bool
is_unique_segment_for_sections_specified() const
{ return this->unique_segment_for_sections_specified_; }
void
set_unique_segment_for_sections_specified()
{ this->unique_segment_for_sections_specified_ = true; }
// For incremental updates, allocate a block of memory from the
// free list. Find a block starting at or after MINOFF.
off_t
allocate(off_t len, uint64_t align, off_t minoff)
{ return this->free_list_.allocate(len, align, minoff); }
unsigned int
find_section_order_index(const std::string&);
// Read the sequence of input sections from the file specified with
// linker option --section-ordering-file.
void
read_layout_from_file();
// Layout an input reloc section when doing a relocatable link. The
// section is RELOC_SHNDX in OBJECT, with data in SHDR.
// DATA_SECTION is the reloc section to which it refers. RR is the
// relocatable information.
template<int size, bool big_endian>
Output_section*
layout_reloc(Sized_relobj_file<size, big_endian>* object,
unsigned int reloc_shndx,
const elfcpp::Shdr<size, big_endian>& shdr,
Output_section* data_section,
Relocatable_relocs* rr);
// Layout a group section when doing a relocatable link.
template<int size, bool big_endian>
void
layout_group(Symbol_table* symtab,
Sized_relobj_file<size, big_endian>* object,
unsigned int group_shndx,
const char* group_section_name,
const char* signature,
const elfcpp::Shdr<size, big_endian>& shdr,
elfcpp::Elf_Word flags,
std::vector<unsigned int>* shndxes);
// Like layout, only for exception frame sections. OBJECT is an
// object file. SYMBOLS is the contents of the symbol table
// section, with size SYMBOLS_SIZE. SYMBOL_NAMES is the contents of
// the symbol name section, with size SYMBOL_NAMES_SIZE. SHNDX is a
// .eh_frame section in OBJECT. SHDR is the section header.
// RELOC_SHNDX is the index of a relocation section which applies to
// this section, or 0 if none, or -1U if more than one. RELOC_TYPE
// is the type of the relocation section if there is one. This
// returns the output section, and sets *OFFSET to the offset.
template<int size, bool big_endian>
Output_section*
layout_eh_frame(Sized_relobj_file<size, big_endian>* object,
const unsigned char* symbols,
off_t symbols_size,
const unsigned char* symbol_names,
off_t symbol_names_size,
unsigned int shndx,
const elfcpp::Shdr<size, big_endian>& shdr,
unsigned int reloc_shndx, unsigned int reloc_type,
off_t* offset);
// After processing all input files, we call this to make sure that
// the optimized .eh_frame sections have been added to the output
// section.
void
finalize_eh_frame_section();
// Add .eh_frame information for a PLT. The FDE must start with a
// 4-byte PC-relative reference to the start of the PLT, followed by
// a 4-byte size of PLT.
void
add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data,
size_t cie_length, const unsigned char* fde_data,
size_t fde_length);
// Remove .eh_frame information for a PLT. FDEs using the CIE must
// be removed in reverse order to the order they were added.
void
remove_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data,
size_t cie_length, const unsigned char* fde_data,
size_t fde_length);
// Scan a .debug_info or .debug_types section, and add summary
// information to the .gdb_index section.
template<int size, bool big_endian>
void
add_to_gdb_index(bool is_type_unit,
Sized_relobj<size, big_endian>* object,
const unsigned char* symbols,
off_t symbols_size,
unsigned int shndx,
unsigned int reloc_shndx,
unsigned int reloc_type);
// Handle a GNU stack note. This is called once per input object
// file. SEEN_GNU_STACK is true if the object file has a
// .note.GNU-stack section. GNU_STACK_FLAGS is the section flags
// from that section if there was one.
void
layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
const Object*);
// Layout a .note.gnu.property section.
void
layout_gnu_property(unsigned int note_type,
unsigned int pr_type,
size_t pr_datasz,
const unsigned char* pr_data,
const Object* object);
// Merge per-object properties with program properties.
void
merge_gnu_properties(const Object* object);
// Add a target-specific property for the output .note.gnu.property section.
void
add_gnu_property(unsigned int note_type,
unsigned int pr_type,
size_t pr_datasz,
const unsigned char* pr_data);
// Add an Output_section_data to the layout. This is used for
// special sections like the GOT section. ORDER is where the
// section should wind up in the output segment. IS_RELRO is true
// for relro sections.
Output_section*
add_output_section_data(const char* name, elfcpp::Elf_Word type,
elfcpp::Elf_Xword flags,
Output_section_data*, Output_section_order order,
bool is_relro);
// Increase the size of the relro segment by this much.
void
increase_relro(unsigned int s)
{ this->increase_relro_ += s; }
// Create dynamic sections if necessary.
void
create_initial_dynamic_sections(Symbol_table*);
// Define __start and __stop symbols for output sections.
void
define_section_symbols(Symbol_table*);
// Create automatic note sections.
void
create_notes();
// Create sections for linker scripts.
void
create_script_sections()
{ this->script_options_->create_script_sections(this); }
// Define symbols from any linker script.
void
define_script_symbols(Symbol_table* symtab)
{ this->script_options_->add_symbols_to_table(symtab); }
// Define symbols for group signatures.
void
define_group_signatures(Symbol_table*);
// Return the Stringpool used for symbol names.
const Stringpool*
sympool() const
{ return &this->sympool_; }
// Return the Stringpool used for dynamic symbol names and dynamic
// tags.
const Stringpool*
dynpool() const
{ return &this->dynpool_; }
// Return the .dynamic output section. This is only valid after the
// layout has been finalized.
Output_section*
dynamic_section() const
{ return this->dynamic_section_; }
// Return the symtab_xindex section used to hold large section
// indexes for the normal symbol table.
Output_symtab_xindex*
symtab_xindex() const
{ return this->symtab_xindex_; }
// Return the dynsym_xindex section used to hold large section
// indexes for the dynamic symbol table.
Output_symtab_xindex*
dynsym_xindex() const
{ return this->dynsym_xindex_; }
// Return whether a section is a .gnu.linkonce section, given the
// section name.
static inline bool
is_linkonce(const char* name)
{ return strncmp(name, ".gnu.linkonce", sizeof(".gnu.linkonce") - 1) == 0; }
// Whether we have added an input section.
bool
have_added_input_section() const
{ return this->have_added_input_section_; }
// Return true if a section is a debugging section.
static inline bool
is_debug_info_section(const char* name)
{
// Debugging sections can only be recognized by name.
return (strncmp(name, ".debug", sizeof(".debug") - 1) == 0
|| strncmp(name, ".zdebug", sizeof(".zdebug") - 1) == 0
|| strncmp(name, ".gnu.linkonce.wi.",
sizeof(".gnu.linkonce.wi.") - 1) == 0
|| strncmp(name, ".line", sizeof(".line") - 1) == 0
|| strncmp(name, ".stab", sizeof(".stab") - 1) == 0
|| strncmp(name, ".pdr", sizeof(".pdr") - 1) == 0);
}
// Return true if RELOBJ is an input file whose base name matches
// FILE_NAME. The base name must have an extension of ".o", and
// must be exactly FILE_NAME.o or FILE_NAME, one character, ".o".
static bool
match_file_name(const Relobj* relobj, const char* file_name);
// Return whether section SHNDX in RELOBJ is a .ctors/.dtors section
// with more than one word being mapped to a .init_array/.fini_array
// section.
bool
is_ctors_in_init_array(Relobj* relobj, unsigned int shndx) const;
// Check if a comdat group or .gnu.linkonce section with the given
// NAME is selected for the link. If there is already a section,
// *KEPT_SECTION is set to point to the signature and the function
// returns false. Otherwise, OBJECT, SHNDX,IS_COMDAT, and
// IS_GROUP_NAME are recorded for this NAME in the layout object,
// *KEPT_SECTION is set to the internal copy and the function return
// false.
bool
find_or_add_kept_section(const std::string& name, Relobj* object,
unsigned int shndx, bool is_comdat,
bool is_group_name, Kept_section** kept_section);
// Finalize the layout after all the input sections have been added.
off_t
finalize(const Input_objects*, Symbol_table*, Target*, const Task*);
// Return whether any sections require postprocessing.
bool
any_postprocessing_sections() const
{ return this->any_postprocessing_sections_; }
// Return the size of the output file.
off_t
output_file_size() const
{ return this->output_file_size_; }
// Return the TLS segment. This will return NULL if there isn't
// one.
Output_segment*
tls_segment() const
{ return this->tls_segment_; }
// Return the normal symbol table.
Output_section*
symtab_section() const
{
gold_assert(this->symtab_section_ != NULL);
return this->symtab_section_;
}
// Return the file offset of the normal symbol table.
off_t
symtab_section_offset() const;
// Return the section index of the normal symbol tabl.e
unsigned int
symtab_section_shndx() const;
// Return the dynamic symbol table.
Output_section*
dynsym_section() const
{
gold_assert(this->dynsym_section_ != NULL);
return this->dynsym_section_;
}
// Return the dynamic tags.
Output_data_dynamic*
dynamic_data() const
{ return this->dynamic_data_; }
// Write out the output sections.
void
write_output_sections(Output_file* of) const;
// Write out data not associated with an input file or the symbol
// table.
void
write_data(const Symbol_table*, Output_file*) const;
// Write out output sections which can not be written until all the
// input sections are complete.
void
write_sections_after_input_sections(Output_file* of);
// Return an output section named NAME, or NULL if there is none.
Output_section*
find_output_section(const char* name) const;
// Return an output segment of type TYPE, with segment flags SET set
// and segment flags CLEAR clear. Return NULL if there is none.
Output_segment*
find_output_segment(elfcpp::PT type, elfcpp::Elf_Word set,
elfcpp::Elf_Word clear) const;
// Return the number of segments we expect to produce.
size_t
expected_segment_count() const;
// Set a flag to indicate that an object file uses the static TLS model.
void
set_has_static_tls()
{ this->has_static_tls_ = true; }
// Return true if any object file uses the static TLS model.
bool
has_static_tls() const
{ return this->has_static_tls_; }
// Return the options which may be set by a linker script.
Script_options*
script_options()
{ return this->script_options_; }
const Script_options*
script_options() const
{ return this->script_options_; }
// Return the object managing inputs in incremental build. NULL in
// non-incremental builds.
Incremental_inputs*
incremental_inputs() const
{ return this->incremental_inputs_; }
// For the target-specific code to add dynamic tags which are common
// to most targets.
void
add_target_dynamic_tags(bool use_rel, const Output_data* plt_got,
const Output_data* plt_rel,
const Output_data_reloc_generic* dyn_rel,
bool add_debug, bool dynrel_includes_plt);
// Add a target-specific dynamic tag with constant value.
void
add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val);
// Compute and write out the build ID if needed.
void
write_build_id(Output_file*, unsigned char*, size_t) const;
// Rewrite output file in binary format.
void
write_binary(Output_file* in) const;
// Print output sections to the map file.
void
print_to_mapfile(Mapfile*) const;
// Dump statistical information to stderr.
void
print_stats() const;
// A list of segments.
typedef std::vector<Output_segment*> Segment_list;
// A list of sections.
typedef std::vector<Output_section*> Section_list;
// The list of information to write out which is not attached to
// either a section or a segment.
typedef std::vector<Output_data*> Data_list;
// Store the allocated sections into the section list. This is used
// by the linker script code.
void
get_allocated_sections(Section_list*) const;
// Store the executable sections into the section list.
void
get_executable_sections(Section_list*) const;
// Make a section for a linker script to hold data.
Output_section*
make_output_section_for_script(const char* name,
Script_sections::Section_type section_type);
// Make a segment. This is used by the linker script code.
Output_segment*
make_output_segment(elfcpp::Elf_Word type, elfcpp::Elf_Word flags);
// Return the number of segments.
size_t
segment_count() const
{ return this->segment_list_.size(); }
// Map from section flags to segment flags.
static elfcpp::Elf_Word